If Time does not exist what is an alternative interpretation of Time Dilation?

Apr 5, 2020
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A Quantum Mechanical Interpretation of the Consequences of Special Relativity






Einstein's theory of Special Relativity

Einstein's theory of Special Relativity predicts that for objects travelling at a significant fraction of the speed of light time dilates. Experimental observations are in agreement with the predictions. For example ordinarily short lived particles such as Muons when at rest are observed by a stationary observer to exist for significantly longer periods when travelling at speeds approaching the speed of light.



Mathematically Speed = Distance/Time



As the speed of light is expected to be constant in any frame of reference (consequent to Maxwell’s equations) the mathematical conclusion for the increased lifespan of Muons traveling close to the speed of light would be that the values for distance and/or time have changed.



  • In the Muon’s inertial frame of reference the distance travelled by the Muons has decreased.


  • In the observer’s inertial frame of reference time has slowed down for the Muons allowing them to live longer.


The difficulty with understanding such mathematically derived conclusions is that they are counterintuitive (which is not to say that they are wrong). Copious experimental observations illustrate clearly and consistently that clocks slow down when in motion precisely as predicted by Special relativity. Thus for example we can confidently predict that an astronaut travelling at near light speed for a year will return to Earth biologically younger than his twin brother by around thirty years.



A typical explanation of Time Dilation is that time flows at a slower rate for the astronaut than for his twin brother on Earth. The analogy of time flowing conjures up images of water moving along in a river. But as time does not appear in any real sense to be a tangible identifiable substance like water can it truly be said to be flowing at different rates? The passage of time can only be measured indirectly in terms of a perceived interval between events. The most accurate measurement of time is currently in terms of the interval between 2 quantum mechanical conditions of a Cesium 133 atom. But what really is it that we are measuring when we state that we are measuring time?



Does Time exist?


Physics defines Time as “that which is measured by clocks”; that is all. There is no evidence to substantiate that time exists as part of the fabric of the universe. It is probable that human beings dreamt up the notion of time as a convenient way of 2 or more people being in the same location to share a task. For example an agreement for 2 people to meet for a hunt at sunrise on the bank of a river next to a large rock is in effect a synchronisation of the event of sunrise with 2 people and a unique geographical point on the planet. The human notion of time serves the purpose of accurately synchronising events for a species that owes much of its success to organised cooperative behaviour.



Although today we would associate sunrise with a specific time indicated on a wristwatch (or more accurately an atomic clock) there is no "known" absolute benchmark of time in any inertial frame of reference. i.e. there is no "known" universal standard time anywhere in the universe with or without the relativistic effects of speed and gravity. Significantly the sunrise over our spot on the river will never be precisely at the same local time from any one sunrise to any other sunrise as measured by an atomic clock situated by the rock. This is due in part to perpetual changes in the orbit of the Earth and in part to the uncertainty of the location and velocity of quantum particles. Quantum observations suggest that it may be impossible to predict or measure the precise local time of any event in the universe. Without any direct evidence of its existence as part of the fabric of the universe it is perhaps more useful to think of time as being an imaginary interval between 2 events.



Can there be a more intuitive way of explaining the observations predicted by special relativity?




The observation that high speed Muons last longer than Muons at rest could be interpreted in one of the following two ways:



  1. Muons decay at the same rate regardless of their speed. The speed of a Muon causes time to slow down in its inertial frame of reference so that for a stationary observer for whom time is running faster a high speed Muon appears to decay more slowly than a stationary Muon. “Proper time” is the time experienced by the Muon in its inertial frame of reference being less than the time measured by the stationary observer calculated as per the following expression.

equation 1.jpg



  1. Muons decay at a rate that reduces according to their speed relative to a stationary observer. “Proper events” is the reduced number of decay events experienced by the Muons in their inertial frame of reference as compared with the higher number of decay events observed by the observer calculated as per the following expression.

equation 2.jpg






The first interpretation founded on Special Relativity is based on the assumption that time is part of the fabric of the universe and that time literally flows at one rate for a stationary observer and at a reduced rate for the particles in motion relative to the stationary observer.



The second (alternative) interpretation assumes that time is merely a human notion and is not part of the fabric of the universe in any real sense. In this case time dilation is no longer a plausible explanation for the increased life span of high speed Muons. Since time dilation can no longer be an explanation the inference is that the high speed Muons last longer than relatively stationary Muons as a direct consequence of their relative speed.



Whilst Particles such as Muons are observed to decay into different particles it is not understood what exactly triggers the change but it is typically characterised as the spontaneous process of one elementary particle transforming into other elementary particles without any apparent external cause. There would seem to be 2 plausible interpretations:



  1. Quantum particles decay or transform spontaneously without any external influence.


  1. Quantum particles decay or transform due to the influence of quantum events in their vicinity.


In the first interpretation the notion that a fundamental indivisible particle may transform itself with no external influence is both counter-intuitive and inconceivably difficult to conclude from experimental observation, which is not to say that it is necessarily incorrect.



In the second interpretation, from the assumption that particle decay is influenced by other quantum events in the vicinity it follows that the rate of decay would be governed by the frequency of such quantum events.



From the same assumption that particle decay is influenced by other quantum events in the vicinity it follows that the frequency of quantum events would be governed by the values of influential properties of the quantum particles such as angular momentum.



Based on observations of particle decay being ******** in a highly predictable way according to the speed of the particles relative to a stationary observer we can further infer that the values of influential properties of quantum particles in a given inertial frame reduce with respect to the speed of the quantum particles. By considering the wave properties of a quantum particle the inference would be that the energy of the wave is reduced through dissipation over a longer distance.



An atomic clock detects an arbitrarily prescribed number of changes between 2 quantum mechanical states of Cesium 133 atoms and registers this as one second of time. A moving atomic clock detects fewer changes than a relatively stationary clock. According to Special Relativity this is due to time slowing down in the inertial frame of reference of the moving clock. However in this alternative interpretation where time is no longer considered to be a real variable the conclusion is that there are fewer quantum events occurring in the inertial frame of reference of the moving clock as a consequence of its relative inertia.



In any given inertial frame of reference the relative frequency of different types of quantum events would be expected to remain constant such that any specific measurement carried out within an inertial frame of reference would be identical to the same measurement carried out within any other inertial frame of reference. Thus for example the same values would be recorded for the average half life of a Muon at rest measured within any inertial frame of reference.





Conclusion



Special Relativity states that relative motion causes time to dilate. The observational evidence is that relative motion causes clocks to slow down and also causes a reduction in the frequency of all events within a moving inertial frame of reference. Thus whilst time is defined as “that which is measured by clocks” the consequences of Special Relativity do not hold clocks to be special. Although these observations can be characterised as Time dilation there is no evidence to substantiate the material existence of time and that which does not exist cannot dilate.



This alternative interpretation is founded on the same set of observations that substantiate Special Relativity but without invoking the assumed variable of time and instead substituting a relative frequency of quantum events.
 
Nov 12, 2020
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As I consider time, it seems that time and entropy are directed related and that both are actually a measure/guide/indicator of the sundry use of "energy" by a system which is either living or inert or a combination of both. The measurement of time by clocks fits neatly into equations, but what time actually is, whether tangible or not, is beyond nudnicks like me. The above post is appreciated and helpful.
 
Jan 27, 2020
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“People like us, who believe in physics, know that the distinction between past, present, and future is only a stubbornly persistent illusion”. -- Albert Einstein

Hermann Minkowski, Einstein’s one-time teacher and colleague, who gave us the classic interpretation of Einstein’s Special Theory of Relativity. Minkowski introduced the relativity concept of "proper time", the actual elapsed time between two events as measured by a clock that passes through both events. Proper time therefore depends not only on the events themselves but also on the motion of the clock between the events. By contrast, what Minkowski called "coordinate time" is the apparent time between two events as measured by a distant observer using that observer’s own method of assigning a time to an event.

An event is both a place and a time, and can be represented by a particular point in space-time, i.e. a point in space at a particular moment in time. Space-time as a whole can therefore be thought of as a collection of an infinite number of events. The complete history of a particular point in space is represented by a line in space-time (known as a world line), and the past, present and future accessible to a particular object at a particular time can be represented by a three dimensional light cone (or Minkowski space time diagram), which is defined by the limiting value of the speed of light, which intersects at the here-and-now, and through which the object’s world line runs its course.

Light-cone-Causal-future-past-and-the-present-plane-of-the-central-event-.png
researchgate.net

Physicists do not regard time as “passing” or “flowing” in the old-fashioned sense, nor is time just a sequence of events which happen: both the past and the future are simply “there”, laid out as part of four-dimensional space-time, some of which we have already visited and some not yet. So, just as we are accustomed to thinking of all parts of space as existing even if we are not there to experience them, all of time (past, present and future) are also constantly in existence even if we are not able to witness them. Time does not “flow”, then, it just “is”. This view of time is consistent with the philosophical view of the eternal or the block universe theory of time*.

According to relativity, the perception of a “now”, and particularly of a “now” that moves along in time so that time appears to “flow”, therefore arises purely as a result of human consciousness and the way our brains are wired, perhaps as an evolutionary tool to help us deal with the world around us, even if it does not actually reflect the reality.

However, if time is a dimension as Rod Serling of The Twilight Zone has explained, it does not appear to be the same kind of dimension as the three dimensions of space. For example, we can choose to move through space or not, but our movement through time is inevitable, whether we like it or not, and it is often called the "arrow of time"**. In fact, we do not really move though time at all, at least not in the same way as we move through space. Also, space does not have any fundamental directionality (i.e. there is no “arrow of space”, other than the downward pull of gravity, which is actually variable in absolute terms, depending on where on Earth we are located, or whether we are out in space with no gravitational effects at all), whereas time clearly does.

With the General Theory of Relativity, the concept of space-time was further refined, when Einstein realized that perhaps gravity is not a field or force on top of space-time, but a feature of space-time itself. Thus, the space-time continuum is actually warped and curved by mass and energy, a warping that we think of as gravity, resulting in a dynamically shaped space time. In regions of very large masses, such as stars and black holes, space-time is bent or warped into a deep well by the extreme gravity of the masses, an idea often illustrated by the image of a rubber sheet distorted by the weight of a bowling ball.

Time Dilation
Relativity
Time dilation is just one consequence of the Theory of Relativity and curved space-time

Also as a result of Einstein’s work and his Special Theory of Relativity, we now know that rates of time actually run differently depending on relative motion, so that time effectively passes at different rates for different observers traveling at different speeds, an effect known as time dilation. Thus, two synchronized clocks will not necessarily stay synchronized if they move relative to each other. There is also a related effect in the spatial dimensions, known as length contraction, whereby moving bodies are actually foreshortened in the direction of their travel.

Time dilation (as well as the associated length contraction) is negligible and all but imperceptible at everyday speeds in the world around us, although it can be, and has been, measured with very sensitive instruments. However, it becomes much more pronounced as an object’s speed approaches the speed of light ( relativistic speeds). If a spaceship could travel at, say, 99% of the speed of light, a hypothetical observer looking in would see the ship’s clock moving about twice as slow as normal (i.e. coordinate time is moving twice as slow as proper time), and the astronauts inside moving around apparently in slow-motion. At 99.5% of the speed of light, the observer would see the clock moving about 10 times slower than normal. At 99.9% of the speed of light, the factor becomes about 22 times, at 99.99% 224 times, and at 99.9999% 707 times, increasing exponentially. In the largest particle accelerators currently in use we can make time slow down by 100,000 times. At the speed of light itself, were it actually possible to achieve that, time would stop completely.***

Perhaps the easiest way to think of this difficult concept is that, when an object or person moves in space-time, its movement “shares” some of its spatial movement with movement in time, in the same way as some northward movement is shared with westward movement when we travel northwest. What forces this sharing of dimensions is the invariant nature of the speed of light (slightly less than 300,000km/s), which is a fundamental constant of the universe that can never be exceeded. Thus, the slowing of time at relativistic speeds occurs, in a sense, to “protect” the inviolable cosmic speed limit (the speed of light).

It should be noted that, although a spaceship travelling at close to the speed of light would take 100,000 years to reach a distant star 100,000 light years away as judged by clocks on Earth, the astronaut in the spaceship might hardly age at all as he travels across the galaxy. This characteristic of relativistic time has therefore spawned much discussion of the possibility of time travel.

According to Einstein, then, time is relative to the observer, and more specifically to the motion of that observer. This is not to say that time is in some way capricious or random in nature – it is still governed by the laws of physics and entirely predictable in its manifestations, it is just not absolute and universal as Newton thought (see the section on Absolute Time), and things are not quite as simple and straightforward as he had believed.

One casualty of the Theory of Relativity is the notion of simultaneity, the property of two events happening at the same time in a particular frame of reference. According to relativistic physics, simultaneity is NOT an absolute property between events, as had always been taken for granted by Newtonian physics. Thus, what is simultaneous in one frame of reference will not necessarily be simultaneous in another. For objects moving at normal everyday speeds, the effect is small and can generally be ignored (so that simultaneity CAN normally be treated as an absolute property); but when objects approach relativistic speeds (close to the speed of light) with respect to one another, such intuitive relationships can no longer be assumed.

* block universe theory of time - see: https://interestingengineering.com/block-universe-theory-is-the-passing-of-time-an-illusion

** the arrow of time - see: https://www.technologyreview.com/2009/11/03/92960/deriving-the-arrow-of-time/

*** https://www.phy.olemiss.edu/HEP/QuarkNet/time.html

See: http://www.exactlywhatistime.com/physics-of-time/relativistic-time/
 
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